The present invention relates to a compound, spring loaded archery bow and especially to an improved compound spring loaded archery bow having pre-adjustments for the compression spring and positioning of the compression spring housing to accommodate different archers.
The traditional archery bow is comprised of a riser having a hand grip and an arrow rest and a pair of resilient limbs attached to each end of the riser. The resilient limbs of the bow form a resilient spring. The bow string is attached to the free end of each resilient limb so that when the bow string is drawn back from its initial position by an archer to shoot an arrow, the resilient limbs flex to place the bow string under tension. The further the archer draws the bow string back, the more the resilient limbs of the bow are flexed which imparts greater tension to the bow string. When the bow string is released to shoot an arrow, the resilient limbs of the bow snap back to their original position to force the bow string back to its initial position to propel the arrow towards a target. These traditional bows are frequently made of strong composite materials but they do have drawbacks. For instance, once an archer selects a particular archery bow, he is restricted with that bow to a maximum drawing force so that the archer is unable to vary the poundage range for a particular bow.
A compound archery bow uses a levering system and typically has cams and pulleys on the limbs. The limbs which act as a release spring in a compound bow are usually much different than those of a traditional archery bow. Stiffness makes the compound bow more energy efficient than other bows so that they are too stiff to be drawn with a string attached directly to them. A compound bow attaches a bow string to cams or pulleys to give a mechanical level to the bow string. Thus, when you pull the cables on a compound bow, it causes the cams to rotate to bend the limbs of a bow. A compound bow has a rigid handgrip or riser having limbs attached to each end and have the sights and the like attached thereto.
Prior art compound bows have typically used limbs that form leaf springs while other compound bows have used other springs for loading the bow. An earlier spring loaded archery bow can be seen in the D. M. Holmes U.S. Pat. No. 428,912 in which each limb of the bow is connected to a central coil spring passing through a tube to give the back bow increased power. In U.S. Pat. No. 4,458,657 to Stockmar, a compound archery bow is a complicated structure with both a main frame and a handle grip and a bow string tensioning assembly located forward of the main frame. The bow string tensioning assembly is formed by exposed resilient tubes for tensioning the bow string which are stretched and placed in tension when the bow string of the bow is drawn.
In the York U.S. Pat. No. 7,201,161, a compound spring loaded archery bow has separate upper and lower spring tensioning assemblies and cam mechanisms for applying tension to the bow string of the bow. Separate upper and lower spring tensioning assemblies are contained within the upper and lower rigid limbs of the bow so that the bow retains the appearance of a traditional archery bow. In the Dieziger U.S. Pat. No. 6,055,974 a compound bow has a facilitated draw for allowing a bow string to be more easily drawn and uses a pair of coil springs. In the L. J. Mulkey U.S. Pat. No. 2,714,377, an archer's bow uses a pair of coil springs. The Guzzetta U.S. Pat. No. 4,756,295 is a compound bow which uses a toggle-like assembly to improve the accuracy and acceleration of the bow. It utilizes a single coil spring.
The present archery bow is spring loaded with a pair of coiled springs mounted to each limb of the bow, which coil springs are pre-adjustable for both pull and which also allows the spring housings to be adjusted for a particular archer.